Sulfur Dioxide → HCID 596766, compound

HRID 1605216Notes

Reaction equation

HRID 1605216 reaction equation
[CH3:1][O:2][C:3]1[CH:10]=[CH:9][C:6]([O:7][CH3:8])=[CH:5][CH:4]=1.Cl[CH:12]([CH3:15])[CH:13]=[O:14].C1([N+]([O-])=C)CCCCC1.S(=O)=O>C(Cl)Cl.[Ag]>[CH3:1][O:2][C:3]1[CH:10]=[CH:9][C:6]([O:7][CH3:8])=[CH:5][C:4]=1[CH:12]([CH3:15])[CH:13]=[O:14]

Participants

6

Reactant 3

HCID 1119Sulfur Dioxide2×HCID 90161,4-DimethoxybenzeneHCID 86733219HCID 86733219, compound

Product 1

HCID 596766HCID 596766, compound

Reagents, catalysts & solvents 2

HCID 23954SilverCatalystHCID 6344DichloromethaneSolvent2×

Procedure

432 mg of silver tetrafluoborate and 305 mg of hydroquinone dimethyl ether are first introduced into a flask fitted with a cold finger. After fitting a dropping funnel sealed by a serum cap and equipped with a pressure compensating device, the apparatus is evacuated 5 times under a waterpump vacuum and is subsequently filled with dry nitrogen. Sulphur dioxide was then condensed in the apparatus at -20°C until the volume of the solution is 40 ml. A solution of 2-chloropropanal-N-cyclohexylnitrone in 10 ml of absolute methylene chloride is then introduced into the dropping funnel and is added dropwise over the course of 2 hours to the vigorously stirred sulphur dioxide solution. The temperature is kept at -10°C for a further 6 hours and the sulphur dioxide is then pumped off in a waterpump vacuum. Towards the end, fresh methylene chloride is added in portions in order to keep the volume at between 10 and 20 ml. After filtering off the silver chloride (through Celite, with rinsing with 3×15 ml of methylene chloride), the filtrate is vigorously stirred with 60 ml of 5% strength hydrochloric acid for 5 hours and then separated off. After washing with concentrated sodium bicarbonate solution and concentrated sodium chloride solution (each wash solution being extracted with 2×10 ml of methylene chloride), and drying with sodium sulphate, the solution is evaporated and the yellow-brown oil which remains is filtered through 10 g of aluminium oxide IV (column filled with hexane and eluted with 30 ml of hexane and 80 ml of 4:1 hexane-benzene). The concentrated eluate is distilled in a rotating bulb tube at 90°C/2 mm Hg. α-(2,5-Dimethoxy-phenyl)-propionaldehyde is thus obtained.

Workup

  1. customfitted with a cold finger
  2. customsealed by a serum
  3. customcap
  4. customequipped with a pressure
  5. customthe apparatus is evacuated 5 times under a waterpump vacuum
  6. additionis subsequently filled with dry nitrogen
  7. customcondensed in the apparatus at -20°C until the volume of the solution
  8. filtrationAfter filtering off the silver chloride (through Celite, with rinsing with 3×15 ml of methylene chloride)
  9. customseparated off
  10. washAfter washing with concentrated sodium bicarbonate solution and concentrated sodium chloride solution (each wash solution
  11. extractionbeing extracted with 2×10 ml of methylene chloride), and
  12. dry with materialdrying with sodium sulphate
  13. customthe solution is evaporated
  14. filtrationthe yellow-brown oil which remains is filtered through 10 g of aluminium oxide IV (column filled with hexane and eluted with 30 ml of hexane and 80 ml of 4:1 hexane-benzene)
  15. distillationThe concentrated eluate is distilled in a rotating bulb tube at 90°C/2 mm Hg

Sources & evidence

ORD record
ord-c7f604b6c61343f69a359cdf0fa026e0
Source dataset
uspto-grants-1976_04
Patent number
US03950327

Reaction notes

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